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Sunday, May 4, 2014

Back in the saddle

SmartSDR and skimmer running on my new Signature radio and computer

I have a new shiny SDR radio station. I was hit by lightning in 2011. I also started a new practice. I had been an anesthesiologist at a hospital local to my town but they changed provider groups which ment my group was out of a job. A new surgery center was going up so my partner and myself took over that contract. There is a lot to do getting something like this going, plus I have 2 teenagers, so ham radio went on the back burner. The lightning did quite a bit of damage. It took out a transceiver, two amps, 2 antennas, and my computer so I knew it was going to take considerable effort to get it running again.

At Orlando Hamcation this year I chanced to look up the Flex guys on Sunday. It wasn't too busy so I had a chance to look closely at the new Signature line up. Of course they had a 6700 with all 8 panadapters blazing away on one end of the booth and a 6500 blazing away on the other. Gerald Youngblood K5SDR was there and I got to catch up with him. He's an amazing guy and truly has my admiration. I think his spine is made of steel. He had a product in the Flex 5000 that had reached some considerable level of maturity. Yet here he was about to embark on an entirely new architecture. First a little history.

I have been a Flex enthusiast since the early SDR-1000 days.

SDR-1000

This was an amazing radio. The SDR-1000 started as a QEX concept. Gerald decided he wanted to build a radio that was software based with a minimum of hardware. I think the first PowerSDR was coded in visual basic. It worked! I'm not sure how well it worked but it worked. This time (the early 2000's) was an explosive period for SDR in ham radio. There were many interested but the technology at least from a ham perspective was cutting edge. The SDR-1000 allowed for an experimental platform on which to develop this new technology. The Flex community grew into a true collaborative community. There was a cadre of developers internal to the company, a cadre of consultants, people like Bob McGwier N4HY and Frank Brickle AB2KT. Bob is a PhD mathematician and Frank a PhD in music composition. There were others of this caliber who consulted and contributed. Also there were the users, people like me who wanted to see the radio grow from being an experimental platform to a world class contender. The advantage of this radio is, it is plastic. It was mold-able and bendable and grow-able. It had minimal hardware constraint. It was not like any other radio.

I came to the Flex from the Ten Tec Orion, itself a kind of groundbreaking radio. The Orion was a pinnacle of old radio design. Back in the late 70's the ARRL labs came up with a scheme to test radios on an "objective" basis. They came up with reproducible test procedures for things like sensitivity and selectivity and dynamic range and third order intercept. The engineers down in Seivereville decided to beat the ARRL at its own game. They came up with a design that maximized their radios performance based on the ARRL sweepstakes of dynamic range, filter performance, third order blocking etc. It was called the Omni V. Its subsequent: the Omni VI, in all of its iterations continued to guild the performance lily. Finally came the Orion. It was basically an Omni VI with a doo hicky in the last IF that had rudimentary software defined functionality. It was an outstanding radio BUT it had one fatal flaw. Every so often users would clamor for software updates and Ten Tec would comply. The flaw was the chip they were programming ran out of memory. You would poke in a new feature and something else would break. It was fatal. The only solution was new hardware. It was very hard for me to justify a new radio based on some stupid mistake by a design engineer. Ten Tec made good money on the design over the years but they got a bit greedy as well. The strength of the design relied on roofing filters. By the time you got all of the filter bays loaded you increased the cost of your radio by a third. Ten Tec made the new roofing filters in the Orion 2 not compatible with the Orion, so the cost of buying a new radio to make up for the stupid design error became prohibitive. Elecraft came along with the K3 (another Omni V variant) and basically stole Ten Tec's thunder by marketing itself as a SDR radio. In my opinion it is not. In my opinion the K3 is just another continuing version of the Omni V. Its basically an Omni V with a fancier doo hicky in the last IF. Its still basically a radio trying to beat the ARRL numbers rather than advancing the state of the art.

The Flex radio on the other hand is unrelated to the Omni way of thinking. The original design used a computer to manipulate the signal from nearly the git go. Moving to a Flex from the old radios is more akin to moving from an analogue SLR camera to a digital DSLR camera. What happens in the Flex is an analogue signal hits the antenna and soon thereafter is digitized. This is like light hitting the CMOS element in a DSLR. The picture is absorbed into a data file that becomes the reproducible image of the original light. You can take this data file and invert the image, change the contrast, color, sharpness etc with a computer of one type or another. There in lays the power. The ability to not only make a true reproduction as far as the senses are concerned but to be able to easily manipulate the image and make something entirely new.... in other words plastic.

Flex started by using the PC as its heart and brain. In fact the SDRT-1000 hardware was really just a kind of modem (modulator/demodulator). PowerSDR running on the computer was really the brains. The problem was a PC was not really the right tool to run a highly intensive near real time application. The PC is too busy checking I/O and dealing with interupts, checking the mouse, and painting the screen and checking email. In order to do all that house keeping it would forget to do things like form CW characters perfectly and in the exact timing needed. PowerSDR represents a kind of pinnacle of achievement. The radios that run PowerSDR are excellent. I still have a SDR-1000, a F3K and a two receiver F5K and I've had a flat out blast with these radios. Now to the point and this is why I see Gerald as having a backbone of steel.

Instead of following along with the ten years of momentum he had built up PowerSWDR, in other words instead of following the Ten Tec model of creating the Omni V and then gilding the lily for the next 50 years. He decided to take a hard turn and basically start all over with a completely different platform, the signature series of radios. That takes courage! It also shows the level of excellence of the design team he has amassed.

Flex 6700

They call this the "Game Changer" but what the heck does that mean? Tune in for the next edition and find out.